The present invention relates to an automatically-winding window shade of the type provided with a self-winding spring mechanism and a rotation shaft for a pulling cord.
In conventional self-winding window shades of the type under consideration and known as spring window shades the shade material is connected to and wound up on the shaft in which the spring device is positioned. The spring is prestressed by mechanical elements upon lowering of the shade whereby a force occurs, which lifts up the shade when the above mechanical elements of the locking hooks in the spring mechanism are released. A so-called falling rod is positioned at the lower end of the shade material which rod makes the window shade smoothly hang. A pulling cord is secured to the middle of the rod. The mechanical arrangement with the hook-type locking mechanism can be held at a distance from the half-length of the unrolled window shade.
A disturbing fact in the known automatically-winding shades is, however that the cord of the lifted-up shade hangs at the center of the window. The pulling cord in the lowered position of the shade randomly lies on the window-sill or the floor. When the window shade, as usual, is connected to the wall at a relatively high level by supports it is necessary, however, to loosen the cord to completely lower the shade.
Also known are side pulling window shades. At the end of such a shade, an endless cord or string train is provided, which has tassels or balls and extends over the roll which is secured to the shade shaft. The window shade can, with the aid of the endless string train, be lowered and lifted when the shade is advanced at its side. The operation of such side pulling window shades is, however inconvenient because, first a user should stand at the side of the window shade and hold the cord with two hands and pull the same. By pulling the cord at one strand or the other the user lifts the window shade or pulls it down. A repeated loosening of the chord is necessary, which requires additional attempts and is inconvenient.